What is the full text of the password prompt? There isn't a way to remove the password unless you have a valid password to begin with. There are a couple of different passwords the BIOS can ask for. The BIOS password itself, and an SSD password. Dell should be able to give you a password that works if you give them the service tag. If not, then I know there are services offered on eBay that will generate a special password based on the service tag for you.
If it is the SSD password, though, I don't think there's anything that can be done.